root / src / Ganeti / DataCollectors / Diskstats.hs @ d6a7518a
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{-| @/proc/diskstats@ data collector. |
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-} |
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{- |
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Copyright (C) 2013 Google Inc. |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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02110-1301, USA. |
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-} |
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module Ganeti.DataCollectors.Diskstats |
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( main |
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, options |
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, arguments |
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, dcName |
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, dcVersion |
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, dcFormatVersion |
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, dcCategory |
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, dcKind |
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, dcReport |
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) where |
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import qualified Control.Exception as E |
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import Control.Monad |
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import Data.Attoparsec.Text.Lazy as A |
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import Data.Maybe |
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import Data.Text.Lazy (pack, unpack) |
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import qualified Text.JSON as J |
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import qualified Ganeti.BasicTypes as BT |
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import qualified Ganeti.Constants as C |
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import Ganeti.Storage.Diskstats.Parser(diskstatsParser) |
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import Ganeti.Common |
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import Ganeti.DataCollectors.CLI |
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import Ganeti.DataCollectors.Types |
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import Ganeti.Utils |
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-- | The default path of the diskstats status file. |
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-- It is hardcoded because it is not likely to change. |
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defaultFile :: FilePath |
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defaultFile = C.diskstatsFile |
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-- | The default setting for the maximum amount of not parsed character to |
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-- print in case of error. |
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-- It is set to use most of the screen estate on a standard 80x25 terminal. |
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-- TODO: add the possibility to set this with a command line parameter. |
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defaultCharNum :: Int |
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defaultCharNum = 80*20 |
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-- | The name of this data collector. |
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dcName :: String |
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dcName = "diskstats" |
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-- | The version of this data collector. |
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dcVersion :: DCVersion |
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dcVersion = DCVerBuiltin |
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-- | The version number for the data format of this data collector. |
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dcFormatVersion :: Int |
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dcFormatVersion = 1 |
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-- | The category of this data collector. |
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dcCategory :: Maybe DCCategory |
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dcCategory = Just DCStorage |
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-- | The kind of this data collector. |
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dcKind :: DCKind |
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dcKind = DCKPerf |
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-- | The data exported by the data collector, taken from the default location. |
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dcReport :: IO DCReport |
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dcReport = buildDCReport defaultFile |
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-- * Command line options |
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options :: IO [OptType] |
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options = |
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return |
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[ oInputFile |
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] |
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-- | The list of arguments supported by the program. |
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arguments :: [ArgCompletion] |
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arguments = [ArgCompletion OptComplFile 0 (Just 0)] |
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-- | This function computes the JSON representation of the diskstats status. |
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buildJsonReport :: FilePath -> IO J.JSValue |
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buildJsonReport inputFile = do |
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contents <- |
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((E.try $ readFile inputFile) :: IO (Either IOError String)) >>= |
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exitIfBad "reading from file" . either (BT.Bad . show) BT.Ok |
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diskstatsData <- |
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case A.parse diskstatsParser $ pack contents of |
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A.Fail unparsedText contexts errorMessage -> exitErr $ |
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show (Prelude.take defaultCharNum $ unpack unparsedText) ++ "\n" |
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++ show contexts ++ "\n" ++ errorMessage |
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A.Done _ diskstatsD -> return diskstatsD |
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return $ J.showJSON diskstatsData |
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-- | This function computes the DCReport for the diskstats status. |
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buildDCReport :: FilePath -> IO DCReport |
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buildDCReport inputFile = |
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buildJsonReport inputFile >>= |
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buildReport dcName dcVersion dcFormatVersion dcCategory dcKind |
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-- | Main function. |
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main :: Options -> [String] -> IO () |
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main opts args = do |
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let inputFile = fromMaybe defaultFile $ optInputFile opts |
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unless (null args) . exitErr $ "This program takes exactly zero" ++ |
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" arguments, got '" ++ unwords args ++ "'" |
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report <- buildDCReport inputFile |
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putStrLn $ J.encode report |